Philadelphia homicide detectives were seeking to determine Tuesday whether a man arrested in Delaware earlier in the day was the suspect wanted for fatally shooting the manager of a Dunkin’ doughnuts store during a robbery in Fairhill early Saturday.

Philadelphia Chief Inspector Frank Vanore, who oversees the detective bureau, said investigators were working with authorities in Delaware to determine if the man, whom he did not name, shot and killed Christine Lugo after she gave him cash while being threatened at gunpoint — and whether he was connected to any other crimes in either state.

“We’re certainly looking at some similarities that occurred between cases,” Vanore said, declining to offer specifics.

Several news outlets, including CBS3, reported that the man was being investigated for crimes including the fatal shooting of an employee at T-Mobile store during a robbery outside Wilmington in May.

Police in Wilmington did not respond to requests for comment.

Lugo, 41, was fatally shot around 5:30 a.m. Saturday inside the store she managed on the 500 block of Lehigh Avenue.

Police posted surveillance video on YouTube this weekend showing Lugo complying with the man’s demands before he shot her, and they asked the public to help identify him.

The slaying — which came on another violent weekend in the city — devastated Lugo’s relatives and friends, many of whom left candles and notes of remembrance outside the store.